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Auteur Bruno Moreira |
Documents disponibles écrits par cet auteur (2)
Affiner la rechercheDisentangling the role of heat and smoke as germination cues in Mediterranean Basin flora / Bruno Moreira in Annals of Botany, 105 (4) (April 2010)
Titre : Disentangling the role of heat and smoke as germination cues in Mediterranean Basin flora Type de document : Imprimé Auteurs : Bruno Moreira ; J. Tormo ; E. Estrelles ; Juli G. Pausas Année de publication : 2010 Article en page(s) : 627-635 Langues : Anglais (eng) Catégories : [CBNPMP-Thématique] Germination : généralités
[CBNPMP-Thématique] Flore méditerranéenneRésumé : Background and Aims : The role of fire as a germination cue for Mediterranean Basin (MB) plants is still unclear. The current idea is that heat stimulates germination mainly in Cistaceae and Fabaceae and that smoke has a limited role as a post-fire germination cue, in comparison with other Mediterranean-type ecosystems (MTEs), suggesting that fire-stimulated germination is less relevant in the MB than in other MTEs. However, recent studies showed that the assembly of Mediterranean plant communities is strongly driven by post-fire germination, suggesting an important role for fire as a germination cue. We hypothesize that both heat and smoke have important effects on the different post-fire recruitment processes of MB species (e.g. level and rate of germination and initial seedling growth). Methods : To ascertain the role of heat and smoke in the post-fire germination response of MB woody plants, a germination experiment was performed with seven heat and two smoke treatments on 30 MB woody species from seven different families, including species with water-permeable seeds and species with water-impermeable seeds. Key Results : Heat stimulated the germination (probability and rate) of 21 species and smoke in eight species, out of the 30 species studied. In addition, six species showed enhanced initial seedling growth after the smoke treatments. Conclusions : The results suggest that both heat and smoke are important germination cues in a wide range of MB woody species and that fire-cued germination in woody plants of the MB may be as important as in other MTEs. Lien pérenne : DOI : 10.1093/aob/mcq017 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=153147
in Annals of Botany > 105 (4) (April 2010) . - 627-635Moreira, Bruno, Tormo, J., Estrelles, E., Pausas, Juli G. 2010 Disentangling the role of heat and smoke as germination cues in Mediterranean Basin flora. Annals of Botany, 105(4): 627-635.Documents numériques
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Article (2010)URL
Titre : Tanned or Burned: The Role of Fire in Shaping Physical Seed Dormancy Type de document : Imprimé Auteurs : Bruno Moreira ; Juli G. Pausas Année de publication : 2012 Article en page(s) : e51523 Langues : Français (fre) Catégories : [CBNPMP-Thématique] Graines
[CBNPMP-Thématique] SemencesRésumé : Plant species with physical seed dormancy are common in mediterranean fire-prone ecosystems. Because fire breaks seed dormancy and enhances the recruitment of many species, this trait might be considered adaptive in fire-prone environments. However, to what extent the temperature thresholds that break physical seed dormancy have been shaped by fire (i.e., for post-fire recruitment) or by summer temperatures in the bare soil (i.e., for recruitment in fire-independent gaps) remains unknown. Our hypothesis is that the temperature thresholds that break physical seed dormancy have been shaped by fire and thus we predict higher dormancy lost in response to fire than in response to summer temperatures. We tested this hypothesis in six woody species with physical seed dormancy occurring in fire-prone areas across the Mediterranean Basin. Seeds from different populations of each species were subject to heat treatments simulating fire (i.e., a single high temperature peak of 100uC, 120uC or 150uC for 5 minutes) and heat treatments simulating summer (i.e., temperature fluctuations; 30 daily cycles of 3 hours at 31uC, 4 hours at 43uC, 3 hours at 33uC and 14 hours at 18uC). Fire treatments broke dormancy and stimulated germination in all populations of all species. In contrast, summer treatments had no effect over the seed dormancy for most species and only enhanced the germination in Ulex parviflorus, although less than the fire treatments. Our results suggest that in Mediterranean species with physical dormancy, the temperature thresholds necessary to trigger seed germination are better explained as a response to fire than as a response to summer temperatures. The high level of dormancy release by the heat produced by fire might enforce most recruitment to be capitalized into a single post-fire pulse when the most favorable conditions occur. This supports the important role of fire in
shaping seed traits.Lien pérenne : DOI : 10.1371/journal.pone.0051523 Permalink : https://biblio.cbnpmp.fr/index.php?lvl=notice_display&id=153140
in PloS ONE > 7 (12) (2012) . - e51523Moreira, Bruno, Pausas, Juli G. 2012 Tanned or Burned: The Role of Fire in Shaping Physical Seed Dormancy. PloS ONE, 7(12): e51523.Documents numériques
article (2012)URL
